Toy building block



FIG. 1 is a perspective view of the toy building block in accordance with my design;

FIG. 2 is a front view of the toy building block shown in FIG. 1, the rear view, the right side view, and the left side view being identical with the front view;

FIG. 3 is a top view of the toy building block shown in FIG. 1; and,

FIG. 4 is a bottom view of the toy building block shown in FIG. 1.

The broken line showing of the interior recess is for the purpose of illustrating portions of the article that form no part of the claimed design. 

CLAIM The ornamental design for a toy building block, as shown and described. 